Power-transmitting device



Dec. 30, 1958 A s, CHARLAT POWER-TRANSMITTING DEVICE Original FiledMarch 18, 1954 G N.HH.,.|..,....||.........U..H,

llill IIN b1l|ll 2 BY gaat! ATTORNEY?%` rownn-TRANsMirTING DEVICEOriginal application March 18, 1954, Serial No. 417,103.

Divided and this application October 4, 1956, Serial N o. 613,932

3 Claims. (Cl. 192-67) This invention relates to power-transmittingdevices or clutches for connecting a pair of coaxial members, such as adriving shaft and a driven shaft, for rotation in unison. Moreparticularly, the invention is concerned with a novel clutch, which canbe quickly engaged and disengaged and functions to provide a connectioninitially maintained by friction but becoming positive in the event ofslight relative angular movement between the members connected. Theclutch of the invention may be employed for a wide variety of purposesand offers special advantages when used in a drilling machine of theturret type for connecting the machine spindle to the turret spindle, towhich the tool to be put into use is attached. A form of the new clutchincorporated in the turret of the drilling machine disclosed in myco-pending application, Serial No. 417,103, tiled March 18, 1954, ofwhich this application is a division, will, accordingly, beillustratedand described in detail for purposes of explanation.

The new clutch includes a driver element and a driven element, one ofwhich has a tapered axial recess formed with one or more bores lyingparallel to its axis and opening through the inner surface of therecess. The second element has a tapered end section adapted to bereceived with a driving lit in ti e tapered recess of the first elementand, in addition, has one or more axial openings extending inwardthrough its tapered surface. Each of the bores contains a pin acted onby a spring and, normally, the end portion of the pin is exposed beyondthe end of the bore. When the clutch is to be engaged, the elements aregiven a relative axial movement, which causes the tapered end section toVenter the tapered recess. As this action occurs, the pins projectingout of the bores will ordinarily not enter the axial openings, so that,as the elements move together, the pins are forced back into their boresagainst the springs and the elements have a friction connection only.However, if the load applied to the clutch is such as to cause slippagein the frictional connection, such slippage will ultimately bring thepins into alignment with the axial openings, so that the pins will enterthe openings and establish a positive connection between the elements.

For a better understanding of the invention, reference may be made tothe accompanying drawing, in which Fig. l is a vertical sectional viewwith parts shown in elevation and other parts broken away of a turretdrilling machine contained the new clutch, the clutch elements beingdisengaged;

Fig. 2 is a vertical sectional view showing the clutch of Fig. 1 withthe elements engaged;

Fig. 3 is a fragmentary elevational view showing the means for operatingthe clutch; and

Fig. 4 is a fragmentary sectional view on the line 4 4 of Fig. 3.

In the drawing, the clutch is shown in the drilling machine of my priorapplication and the machine includes a housing 10, in which a quill 11is mounted for vertical movement. The quill is formed with rack teeth11a meshing with a pinion 12 on a shaft 13, which is mountedfor rotation'in bearings in housing 10 and is rotatable by spokes 14 to raise andylower the quill.

A spindle '15 ismounted for rotation in upper and lower ball bearings inthe quill, the lower bearing 16 only being shown. The inner 'and outerraces of bearing 16 are seated at their upper ends againstcircumferential shoulders on the quill and spindle, respectively, and'the lower end of the outer race is seated on the upper end of a bearingcap17 threaded into the lower end of the quill. The inner race is heldin place against the shoulder on the spindle by'a lock nut 18 threadedo-n the spindle.

The quill projects below the lower'end of housing 1li and enters arecess in the' upper housing 19a of a turret 19. A lower collar 20 istelescoped over the lower end of the'bearing cap 17 and isA secured tocap 17 by any suitable means. Thecollar has a circumferential flange,upon which is seated a coil spring 21 encircling the quill. At its upperend, the spring'bears against the radial flange of an upper'collar 22,which lies in the upper end of the recess in housing 19a and is'securedin place in the recess in any suitable way.

The spindle '15 projects below the lower end of the quill and a collar23 is threaded on the projecting end of the spindle and has an axialflange spaced from the spindle and internally threaded. The spindleprojects below the lower end of collar 23 and has a tapered end section15a with a diametric groove in its free end.

A'driver element 24 is mounted on the lower end of the spindle and it isformed with a neck 24a, which is threaded into the iiange 23a of collar23. The element has a tapered internal bore, which receives the taperedend section 15a of the spindle. A pin 25 extends across they bore in thedriver element 24 in position to be received 'in the diametric groove inthev lower end of the spindle. The driver element has a tapered axialrecess 26 at its lower end and it is'formed with one or more bores 27lying parallel to the axis and extending downward from its upper end to'openpartiallythrough the surface of the recess 26. Each bore containsVa pin 27a, which is'forced downwardly by a spring 28 bearing againstthe pin and held in place by a plug 29 threaded into the upper end ofthe bore. When a pin is seated against the lower end of its bore, aportion of the pin lies exposed within the recess.

A lower housing 19h is pivotally mounted on the upper housing 19a forrotation on an axis at an angle to the axis of spindle 15. The lowerhousing is provided with a plurality of recesses arranged in a circularseries concentric with the axis of rotation of the housing and eachrecess contains a turret spindle 30. Each spindle has a head 31projecting into the interior of the housing beyond its recess and formedwith a tapered circumferential surface, so that the head may enter therecess 26 at the lower end of the driver element 24 with a driving lit.

The head 31 of each turret spindle is provided with openings 31a in itstapered surface in position to receive the pins 27 on the driver elementwhen the head enters recess 26. Below its head 31, each turret spindlehas a radial ange 32, the under surface of which rests upon a group ofballs 33 in a spacing ring 34. The balls run upon the flat upper surfaceof a bearing ring 35, which has a lower surface of spheroidal contourresting upon a similar surface on a bearing ring 36 seated in part uponthe bottom of the recess in the housing and in part upon a flat sealingring 37 lying between the bearing ring 36 and the bottom of the recess.The inner edge of the sealing ring 37 lies close to the surface of thespindle 30 and the several parts of the bearing lie within a sleeve 38,which is seated upon the bottom of the recess and has an internal angeat its top overlying the flange 32 on spindle 30. The sleeve 38 is heldin place by a snap ring 39 in an internal channel in the side wall ofthe recess.

In the use of the drilling machine, kthe quill is raised by rotation ofshaft 13 and pinion 14, whenever adifferent tool in the housing 19b isto be4 brought into effective position. `As the quill rises, the uppercollar 22 engages the bottom surface of housing and the upward movementof the quill thereafter causes the spring 21 to be compressed betweenthe collars 20 and 22 and the driver element 26 to be separated from thehead 31 on the spindle directly beneath it. When the driver element hasbeen moved to the position shown in Fig. 1, the lower housing 19b isrotated to bring the turret spindle carrying the desired tool beneaththe main driving spindle and the connection between the driver element26 and the turret spindle now in effective position is established bylowering the quill. In the downward movement of the quill, the driverelement 26 telescopes over the tapered head 31 on the turret spindlebeneath it and a driving tit between the driver elementfand the head ofthe turret spindle is established. Any .misalignment of the turretspindle with relation to the driver element is corrected by reason ofthe mounting of the turret spindle on the bearing resting on the members35 and 36 with engaging surfaces of spherical contour.

Ordinarily, when the elements of the clutch are engaged as described,the pins 27 will not enter the openings 31d in the turret spindle ineffective position, so that there will be a frictional connection onlybetween the clutch elements. However, if any slippage in the clutchoccurs, the relative angular movement of the driver element and of theturret spindle will ultimately bring the pins 27 in alignment with theopenings 31a andthe pins will at once enter the openings, so that theclutch elements are held positively against relative angular movement.

In the form of the clutch illustrated, the driver element has been shownas of the female type and the end sections on the tool spindles as malein form, but it will be evident that the opposite arrangement could beused, if desired. Also, the pins could be mounted in bores in the toolspindles and the driver element could be formed with axial openings toreceive the pins. The arrangement illustrated is preferred, since it ismore difficult to make a female element with the desired accuracy than aI claim:

`1. VA clutch for connecting a driving member and a driven member, whichcomprises a pair of elements adapted to be mounted on the respectivemembers, first element having an axial-recess open toward the second andtapering in diameter inwardly and the second element having an endsection tapering in diameter toward its free end, the end section beinginsertable into the recess to provide a frictional driving connectionbetween the elements, first element having at least one bore lyingparallel to and offset from its axis and opening through the wall of therecess, a spring-pressed pin in the bore normally projecting out of thebore into the recess, and the second element having at least one openingextending inward from the tapered surface of its end section and adaptedto receive the pin when the end section is within the recess and theelements are in the proper angular relationship.

2. The clutch of claim l, in which the element with the axial recess ismounted on the driving member and the element with the tapering endsection is mounted on the driven member.

3. The combination of driving and driven shafts, a

l fixed bearing for one shaft, a seat of spherical curvature encirclingthe second shaft, a bearing for the second shaft movably mounted on theseat, a member mounted on the end of one shaft and having an axialrecess formed I with a circumferential surface increasing in diameterinsertable into the recess to provide a driving connection male elementand it is, therefore, advantageous to ernbetween the members, eachmember having at least one bore lying parallel to and offset from itsaxis and opening through said circumferential surface of the member, anda spring-pressed pin in the bore of one member adapted to be received inthe bore of the other member to connect the members positively.

References Cited in the file of this patent UNITED STATES PATENTS305,372 Burdict Sept. 16, 1884 1,092,211 Grove Apr. 7, 1914 1,248,583Will Dec. 4, 1917 1,618,470 Patterson Feb. 22, l927 2,070,154 CarterFeb. 9, 1937 2,097,922 Hodgson Nov. 2, 1937

